Ger Brennan has a quick and cutting response to the doubters of Dublin’s defensive line ahead of it’s biggest test of the summer.

There has been a perceived weakness in the Dubs’ full-back line.

And Blues fans are hoping the creaks that showed up in the Leinster final against Meath and the All-Ireland quarter-final against Cork are not exposed on Sunday.

After all, it’s the old enemy Kerry who are next up for the Blues with a place in the final against Mayo at stake.

But quiz Brennan on the issue and his answer is clear - it’s Dublin who are still in contention for the Sam Maguire Cup, not Meath or Cork.

“Well, the last two teams (we played)...they’re not in the championship,” said the experienced centre-back.

“Touche. So, they can kick it in as they want - Not being smart, and with all due respect to their efforts.

“You work on all aspects. I’ve heard stuff - ‘the full-back line is struggling under the high ball’ - but results have shown we’re winning matches.

“As a half-back line and midfield, you try and come in and support your full-backs as well.

“That’s something we’ve continually worked on since January.”

But of course the idea that the Kingdom will pose serious problems is not news to Brennan.

Dublin’s ‘startled earwigs’ were left traumatised by the demolition dished out by Kerry in the 2009 All-Ireland quarter-final, although tellingly Brennan missed out through suspension.

He was back two years later for the ultimate revenge - the All-Ireland final victory.

I was in the stand watching in 2009,” the schoolteacher recalled. “I had a nice Cornetto that day.

“But, looking back now and over previous seasons - particularly when Pillar (Paul Caffrey) was manager - Dublin were the ‘next best thing’ and I think lads got quite caught up with that within the squad and that affected their performances.

“We duly received those lessons but it took us a long time to learn from them - up until Pat (Gilroy) came in, to be honest with you.”

He added: “Kerry have set the benchmark for decades, along with the like of Tyrone and Cork and recently Donegal.

“So if you want to be the best you have to beat the best that’s out there. You have to challenge yourself and you have to get the best out of yourself.”

That certainly applies to the 28-year-old himself in two days’ time as he faces one of the greatest tests of his career.

Brennan is set to come face to face with Colm ‘Gooch’ Cooper, who has been switched by Eamonn Fitzmaurice to the centre-forward position to great effect this year.

“Colm seems to have a new lease of life,” said the -year-old. “He’s an extremely talented footballer.”

The St Vincent’s man admits that when Cooper was in the full-forward line, defences would try to push him away from goal or to force him to pass because of his scoring threat.

“Over the years I’ve played on him at times when he would drift out or you might be caught in there,” Brennan said.

“In the modern game the forward-lines in particular are quite inter-changeable.

“They do try and confuse the defenders, which works quite a lot of the time.

“As a defender, you’re trying to keep your shape as best that you can and not get caught up with all that movement. Whoever’s in there is in there.

“They have such a strong forward-line and they’re all such skilful players that I’d say they might mix it around.

“We’ll just prepare for every eventuality as best as possible, but they get the ball up quite cleverly up to the inside forward-line.

“They have the option of high ball in or playing it in low. That’s worrying as a defence because quite often a team might just have one tactic.

“I know the last day Cork hit in quite a lot of high ball and didn’t seem to change it too much.

“I don’t think Kerry will do that. They’ll mix it up and keep us on our toes.

“But we won’t get overly caught up with them either. There will come a time when we have to focus on ourselves as well.”

The history of Dublin v Kerry is a special subject that Ger Brennan has been swotting up on.

But the teak-tough defender says he’s now totally focused on making history in this storied fixture – not reading about it.

Two Christmases ago he got a present from his parents of the Dublin v Kerry book that documents the rivalry.

“I really enjoyed reading some of the stories that are in there,” said the teak-tough defender.

“At that stage in my career, I certainly enjoyed the rivalry between both squads.

“But, as a player, you’re not afforded that privilege to get caught up in nostalgia.

“You really have to focus on the present, and the current Kerry team and what they bring.

“And also trying to put our own influence on the game.”

Remarkably, Dublin’s 2011 All-Ireland final win was their first championship success over Kerry since 1977.

“I don’t know if it impacts too much on this Dublin panel because a lot of the young lads coming up don’t get caught up in it,” he said.

“We were a couple of years younger coming up so didn’t get caught up in it either. You’re going out to win.”

Ger Brennan insists there had to be a clear-out in the Dublin ranks after their humiliating defeat to Kerry in 2009.

The Dubs lost by a whopping 17 points in the All-Ireland quarter-final – in a game that spelt out to then Blues boss Pat Gilroy (inset) what had to be done.

Two years later, Dublin were All-Ireland champions, and the rate of change within the ranks has continued apace.

However Brennan has remained a central figure, despite Gilroy’s departure after last year’s semi-final disappointment and Jim Gavin’s arrival.

“I guess it just shows you the depth that’s in Dublin underage football,” said the centre-back.

“There’s young lads coming up and keeping guys on their toes.

“I think after ’09, there was a clean-out of several players. and whether some guys agreed with it or disagreed with it, that had to happen.

“I think in all sport, I would have learned quite quickly that you’re only a resource and as soon as you’re used up the next person comes in.

“That’s just the nature of it and that’s something you have to buy into as a player. You can’t take it personally. And after 2009 there was a massive clear-out.

Brennan added: “The workload involved in senior inter-county hurling and football has really come on over the last 10, 15 years.

“We’re professional in every way bar getting paid. I think most players would agree with that.

“It has changed since I’ve started. The depth of analysis, the focus on athletic development and so on has really grown.”

Brennan admits there are times in a career when a player suffers mental lows.

“That’s quite natural, I think, in any employment or any sport,” he said.

“I’m in the position where I’m fortunate to be playing a lot of the time. It keeps you going.

“The challenge was back when I started off and I was serving my apprenticeship under Pillar (Paul Caffrey) and when I wasn’t getting regular games.

“That was tough. So I’ve seen it from both ends of the spectrum. That’s just the nature of it.”